Power conversion method and apparatus



July 28, 1942. v .J. J. WYDLER 2,291,273

POWER CONVERSION METHOD AND APPARATUS li EXHAUST PERIOD 64 \4 94 I 94 pl:53 n M 5 vb/ 34 WW 4211/ :22:26

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INVENTOR y JOHANN J-WYDLER ATTORNEY July 28, 1942. J. J. WYDLER POWERCONVERSION METHOD AND APPARATUS Original Filed April 11, 1940 3Sheets-Sheet 2 INVENTOfi JOHANN J.WYDLER ATTORNEY July 28, 1942. J. .1.WYDLER POWER CONVERSION METHOD AND APPARATUS Original Filed April 11,1940 3 Sheets-Sheet 3 INVENTOR JOHANN J.WYDLE ATTORNEY Patented July 28,1942 POWER CONVERSION METHOD AND APPARATUS .loharm J. Vi'ydler,l/Vestfield, N. J., assignor, by mesne assignments, to Cities ServiceOil Company, New York, N. Y., a corporation of Pennsylvania Originalapplication April 11, 1940, Serial No. 329,063. Divided and thisapplication January 16, 1941, Serial No. 374,638

12 Claims.

This invention relates to an energy conversion system, and isparticularly concerned with improvements in method and apparatus forutilizing energy of combustion gases under superatmospheric pressure forproducing flow of and compressing other stationary bodies of gas or airunder lower pressure,

A particular object of the invention is to provide improved method andmeans for utilizing the potential energy which is available in the hotwaste exhaust gases discharged from the cylinders of an internalcombustion engine for compressing and pumping air.

The present invention was originally described in my copendingapplication Serial No. 329,063, filed April 11th, 1940, for Gas pumping,of which this is a division.

The gas exhaust period of the cycle of any four stroke cycle internalcombustion engine cylinder consists of two parts. During the first partof the exhaust period just after the exhaust valve has been opened, asubstantial proportion (roughly 50%) of the total weight of gas in thecylinder is rapidly discharged as a high pressure puif Wave movingoutwardly from the cylinder into the exhaust manifold at relatively highinitial pressure and at high velocity. During the latter part of theexhaust period the remaining portion of the exhaust gases leaves thecylinder as a relatively low pressure wave moving in front of theadvancing piston, this period of the cylinder being referred to as thestroke period of the exhaust. During the stroke period of the exhaust,back pressure in the exhaust manifold may interfere markedly with themovement of the piston in the exhausting cylinder.

The operating cycle of the pump of the present invention includes firsta displacement period during which a stationary body of air or other gasis trapped at atmospheric pressure within the pump while beingcompressed and then pushed out of the pump by pressure balancingdisplacement action of a flowing stream of hot engine exhaust gasesintroduced into the pump during the pufi discharge period of a singleengine cylinder exhaust cycle. This displacement period is followed by ascavenging period during which the puff exhaust gases which have beentrapped in the pump during the displacement operation are dischargedfrom the pump and the pump is scavenged with air, preferably by means ofenergy derived at least in part from the exhaust gases which aredischarged from the same engine cylinder during the stroke period of thecylinder exhaust cycle.

Ali thus 55 compressed and discharged from the pump by an operationderiving energy from the hot gas pressure wave discharged from onecylinder of a multi-cylinder engine, may be delivered as supercharge airto another engine cylinder having a coinciding air intake period.

The present invention provides that any assembly of gas pumping unitsand multi-cylinder four cycle engine should include a sufficient numberof engine exhaust manifolds to insure that the exhaust puff waves in anymanifold shall not follow each other at intervals shorter than 180engine crank angle travel. Some of the pumps 0f the present invention,however, are so designed that they can be operated on a cycle which iscompleted within a period encompassed by 120 crank angle travel of theengine supplying the exhaust gas for energizing the pump. Consequently asingle pump may be operated by the pressure waves occurring alternatelyin two exhaust manifolds of a six cylinder engine. Where the pump isalso connected at its air discharge end with one or more air intakemanifolds of the engine for the purpose of supplying compressed air toeach engine cylinder during the last part of its air intake period,provision is made for supplying air at atmospheric pressure to eachengine cylinder during the first part of its air intake period.Consequently the pump need only be of small capacity, and can beassembled in closely spaced relation to the engine, with short air andgas transfer connections.

Another feature which differentiates the pump of the present inventionis in the use of a light, and in some designs, flexible sheet metaldiaphragm or floating piston mounted for reciprocal movement within thepump in response to small pressure differentials applied to oppositefaces thereof, and having low mechanical resistance or inertia tomovement in either direction. The diaphragm or piston serves tosubstantially inhibit contamination of the air or other gas undergoingcompression by the engine exhaust gas; insures more nearly perfectadiabatic compression by reducing transfer of heat; and affords morepositive and efficient scavenging. The diaphragm or piston, therefore,is an important contributing factor in reducing the size of the pump orcompressor to a volumetric capacity not substantially exceeding that ofan engine cylinder, and in permitting efiicient operation of the pumpover a wide speed range.

With the foregoing and other objects and features in view, the inventionconsists in the improved method of and apparatus for converting energyas hereinafter described and more particularly defined by theaccompanying claims.

The invention will be described more particularly by reference to theaccompanying drawings, in which:

Fig. I is a diagrammatic assembly view, showing a single floating pistondisplacement pump operatively connected to exhaust and intake manifoldsof a six cylinder four cycle internal combustion engine; the pump,engine intake and exhaust manifolds, and gas transfer connections andvalve chambers being shown in longitudinal section.

Fig. II is a pressure-time chart showing in full and dotted lines,respectively, the gas pressure waves which can be built up in two engineexhaust manifolds of a six cylinder four cycle engine over a period of/2 engine cycle or one revolution.

Figs. III, IV, V and VI are crosssectional views of the gas and airtransfer control valves taken respectively along the lines III-III,IV-IV, V-V and VI-VI of Fig. I.

Fig. VII is another diagrammatic assembly View showing a single floatingdiaphragm displacement pump and the intakeand exhaust manifolds of a sixcylinder, four cycle engine operatively connected by gas and airtransfer connections and transfer valves (parts being shown inlongitudinal section) Fig. VIII is a schematic view of an assembly of aform of displacement pump equipped with a flexible diaphragm having itsends anchored to the pump housing, said pump having transfer ports atopposite sides of the diaphragm connected to intake and exhaustmanifolds for grouped cylinders of a six cylinder four cycle engine, nohot gas transfer valve being included.

Fig. IX is a plan View of the pump which is illustrated in Fig. VIII,taken on the line IX--IX of Fig. VIII.

Fig. X is an assembly View of two floating piston displacement pumpsarranged in tandem and communicably connected respectively to two engineexhaust manifolds, together with gas and air transfer valves andconnections adapting the pumps for engine supercharging, parts beingshown in longitudinal section.

Fig. XI is a cross-sectional view of the apparatus of Fig. X, taken onthe line XIXI of Fig. X.

Fig. XII is a cross-sectional View through one of the air transfervalves of Fig. X, taken along the line XIIXII of Fig. X.

Figs. XIII, XIV and XV are cross-sectional views of the gas and airtransfer valves, taken respectively along the lines XIIIXIII, XIV-HV,and XV-XV of Fig. X.

Fig. XVI is a diagrammatic assembly view, chiefly in longitudinalsection, showing a pair of floating piston pumps mounted in tandem andeach communicably connected to individual engine exhaust and intakemanifolds, together with gas and air transfer connections and controlvalves.

Fig. XVII illustrates schematically an arrangement of two displacementpumps in tandem with connections to separate engine exhaust manifolds,

no hot gas transfer valves being provided.

Fig. XVIII is a view in longitudinal section through the cylinders ofthe engine of Fig. X looking toward the viewer, showing the pistons,valves and cranks in position for supercharging one cylinder by energyderived from exhaust gases discharged from another cylinder; thedisplacement pumps, manifolds and connections being outlined in dottedlines.

In the apparatus assemblies which are illustrated in Figs. I, VII, X,XI, XVI, XVII and XVIII of the drawings, one or more displacement pumps20 are arranged for the compression and pumping of air by means ofenergy supplied thereto from the hot exhaust gases discharged under lowsuperatmospheric pressure from a six cylinder four cycle internalcombustion engine 24. Within the pumps piston-like floating diaphragms22 are mounted to reciprocate with small clearance for the purpose ofpreventing substantial contact or intermixing between the compressinggas (exhaust gas) and the air or other gas being compressed, therebyinsuring efficient adiabatic compression. The air which is compressed inthe pump by a pressure balancing operation, is illustrated as beingutilized for supercharging the engine cylinders. However, as previouslyindicated, the invention is not limited to the compression of air, norto the use of such air for engine supercharging.

In Figs. X, XI and XVIII, the cylinders of engine 24 have been numberedrespectively 1, 2, 3, 4, 5 and 6; and cylinders 1, 2 and 3 have beenshown with their exhaust ports connected through an exhaust manifold 26and a transfer conduit 5| with one of two pumps 20 arranged in tandem;while the exhaust ports of cylinders 4, 5 and 6 have been shown asconnected through an exhaust manifold 32 and a transfer conduit 53 withthe other pump 23. In Figs. X and XI manifold 26 is also shown asconnected at 21 with the housing of a gas discharge valve 3 l andmanifold 32 is similarly connected at 33 with the housing of acylindrical gas discharge valve 31. Likewise the intake ports ofcylinders 1, 2 and 3 have been shown as connected through an intakemanifold 38 and a carburetor 40 to the housing of an air transfercontrol valve 43; while the intake ports of cylinders 4, 5 and 6 havebeen shown as connected through an intake manifold M and a carbureter 46to the housing of an air transfer control valve 49. The housings ofvalves 43 and 49 are in turn respectively connected to the respectivepumps 20 by forked air transfer conduits 55 and 51. Concentric gasejector nozzles 58 and 60 are connected, respectively, to the housing ofthe valves 3'! and 3f. This apparatus will be hereinafter more fullydescribed.

In Figs. I and VII, the cylinders of engine 24 have been indicateddiagrammatically by the numerals 1, 2, 3, 4, 5 and 6; and cylinders 1, 2

and 3 have been indicated as having their exhaust ports connectedthrough an exhaust manifold 26 and passage 28 to housing 29 of a hot gastransfer control valve 3%; while the exhaust ports of cylinders 4, 5 and6 have been indicated as connected through exhaust manifold 32 andpassage 34 to housing 35 of a hot gas transfer control valve 36.Likewise, the intake ports of cylinders 1, 2 and 3 have been indicatedas connected through an intake manifold 38 and carbureter 40 to housing4| of an air transfer control valve 42; while the intake ports ofcylinders 4, 5 and 6 have been indicated as connected through an intakemanifold 44 and a carburetor 4-5 to housing 41 of an air transfercontrol valve 48. Hot valve housings 29 and 35 are in turn connected toa hot gas intake and exhaust port of pump 20 by a forked transferconduit 52; and cold valve housings M and 4'! are in turn connected toan air intake and exhaust port 54 of pump 20 by a forked air transferconduit 56.

Concentric gas ejector nozzles 53 and 60 are connected, respectively, tothe housings 29 and 35 of the hot gas transfer control valves, andafiord the means by which gas may be discharged from either of theexhaust manifolds or from the pump to atmosphere by way of a Venturithroat 62 and mufiier 64. An atmospheric air intake filter 66 isconnected to housings t! and t? of the air transfer control valves inposition to deliver air at atmospheric pressure to the pump and toeither of the air intake manifolds and carbureters.

The full line pressure time curve of Fig. II shows the successive steeppressure waves built up in an exhaust manifold (such as manifold 26) bythe exhaust gas discharges from two cylinders (for example cylinders 1and 3) over one engine revolution. The exhaust of cylinder 1 beginsabout 45 crank angle before bottom dead center of crank I, producing astrong puff wave which builds up a peak and then subsides within aperiod of about 100 crank angle, and is followed by a smooth weak strokeexhaust extending over about 140 crank angle. The dotted line pressuretime curve of Fig. II shows the successive pressure waves built up inanother exhaust manifold (such as manifold 32) by the exhaust gasdischarged from other engine cylinders (for example cylinders 4 and 5)at periods shifted in phase against the waves produced by gas dischargesfrom cylinders 1 and 3 by half of an exhaust period or by 120 crankangle firing intervals. The pun discharge wave of cylinder 1 occurssimultaneously with the stroke exhaust period of cylinder 4, and thepuff discharge wave developed in manifold 32 by cylinder 5 occurssimultaneously with the stroke exhaust wave of cylinder 1 in manifold25. The pressure waves as portrayed in Fig. II occur in an exhaustpiping system which is continuously open to atmospheric discharge. When,however, discharge of the exhaust gases to atmosphere is temporarilyblocked over the length of a cylinder puff discharge period, thepressure peak of the puff wave may be forced up higher and may bemaintained over a longer period. The subsiding side of the puff wave hasa slope and shape which depends on the rapidity with which the exhaustpiping system is reopened to free atmospheric discharge.

In the single floating piston type displacement pump-engine assemblieswhich are illustrated in Figs. I and VII, the puff discharge Waves whichare produced successively by all six cylinders of engine 24, operatingwith crank angle spacings of 120, are all put to work within the samepump space in rapid succession, which means that the operating cycle ofthe pump must be completed within a time period corresponding to a 120crank angle movement of the engine.

The rotary gas and air transfer valves, arranged respectively betweenthe pump and the engine exhaust manifolds and between the pump and theengine intake system, are activated from the engine crank shaft in themanner illustrated by Fig. VII, the drive being taken for example bychain from the engine shaft to the shaft 72 on which valves 30 and 35are mounted and from shaft 12 to shaft M to which the air pressurevalves 42 and 43 are keyed.

In the operation of all six cylinder four cycle internal combustionengines, the cylinders each fire once during every two enginerevolutions, the cylinders operate on cycles with a crank angle spacingof 120. Thus, while cylinder 1 is starting its gas exhaust, cylinder 6is finishing its air intake; and while cylinder 4 is starting its gasexhaust, cylinder 3 is finishing its air intake; and while cylinder 5 isstarting its gas exhaust, cylinder 2 is finishing its air intake. Inother words, the assemblies of displacementpumps and engine exhaustmanifolds and intake manifolds as illustrated in Figs. 1, VII, X, XVI-and XVIII are designed to pair the cylinders of the multicylinderinternal combustion engine when utilizing energy supplied to the pump bythe engine exhaust waves for supercharging the engine. With the enginecylinders thus paired, energy carried by the exhaust gas discharge fromone cylinder of a pair can be utilized for compressing air andtransferring such air as supercharge air into the other paired cylinderduring the last portion of its air intake period. During the first partof the air intake period of each cylinder, air can be supplied to thecylinder at atmospheric pressure. The pistons in each cylinder of apair, such as 2 and 5, pass simultaneously through their top and bottomdead center positions. However, the power strokes of the pistons are 360crank angle apart in phase. In the case of engines having an unevennumber of cylinders, as for example nine cylinders, the dead centerpositions of the pistons in paired cylinders are not exactly together,for example 40 apart, and therefore the power strokes are apart in phaseless than 360, for example 320.

In the operation of the engine-displacement pump assemblies of Figs. Iand VII three cylinder discharge puff waves are supplied to the pumpfrom the engine discharge manifold system during each engine crank shaftrevolution. These gas discharge waves are designed to produce by meansof the pump three similar air compression waves in the engine intakemanifold system. The rising side of each exhaust puff Wave measures theperiod during which the puff exhaust gas surges into the pump againstthe air, though separated from it by the diaphragm or floating piston,and during this period air is compressed in the pump and discharged fromthe pump to a transfer conduit. The receding side of the puff waverepresents the period during which exhaust gases are released from thepump to atmosphere and the period during which air rebounds from thetransfer conduit into the pump to fill it preliminary to a new operatingcycle. Thus one pump cycle may be said to be completed during the periodspanned between the two points (1-0 in the diagram of Fig. II.

The exhaust gas distributing valves 30 and 33 must operate on cycleswhich correspond with those of the pump, hut also on cycles whichinclude the additional phase of passing the stroke exhaust from eachcylinder directly to the atmospheric discharge systems 52 and E i duringthe second half of each engine cylinder exhaust period. Likewise, eachof the air valves 52 and 58 must complete its cycle during period of thepump cycle, but has to accomplish additional duty of supplyingatmospheric air to the intake manifcids during the first part of the airintake period of each engine cylinder. The hot and cold gas transfervalves may be rotated at a speed 1 times the speed of the e ie crankshaft, or at a straight fracton of such speed, example with a speedcrank shaft speed in the case where each of the valves is provided withtwo opposite of ports. in cc of the single ports possessed by the valvesillustrated in Figs. I and VII. By providing the valves with three setsof ports the speed of the valves may be reduced to the speed of thecrank shaft. With a single pump assembly the number of strokes of thepump piston is always three times the number of revolutions of the crankshaft.

As shown in Figs. I, III and IV, each of the valves 39 and 36 is arotary tubular valve having a bore of annular cross section which opensat one end into the valve chamber and engine manifold connectedtherewith, and which is closed at the other end by a common cylindricalhub joining both valves to shaft 12. Each of the valves 30, 36 has asingle lateral port 25, 39 (Figs. III, IV) extending the full length ofthe valve wall and having a wi th subtending a cylinder arc ofapproximately 120. Each of the air pressure valves 42 and 48 is a rotarycylinder segment subtending an arc of approximately 120 (Figs. V, VI).

Each of the hot gas transfer valves 35 and 36 performs three functionsduring one revolution. During the first part of a cycle of pump 20, oneof the valves rotates to a position permitting passage of engine puffexhaust gases under superatmospheric pressure into the pump from oneexhaust manifold. During the second part of the pump cycle, the valverotates further to open the passage whereby puff exhaust gases trappedin the pump, exhaust manifold, and exhausting cylinder, are released toatmosphere. Also during this last part of the pump cycle and for sometime after the pump cycle is completed, the valve must cut off anyfurther transfer of exhaust gases to the pump and pass stroke exhaustgases from the same engine manifold directly through the engine mufliersystem to the outside atmosphere. In doing so the pump is disconnectedfrom this same exhaust manifold and enabled to perform another pumpingcycle in connection with another branch exhaust manifold.

Similarly, one of the air transfer valves 42 and 48 must operate duringthe first air displacement and compression period of each pump cycle totransfer compressed air from the pump space into the proper engineintake manifold. This period of communication between the pump and theintake manifold extends over all of the displacement and compressionperiod of the pump cycle and over a part of the air rebound period.After completion of the air rebound period, the air transfer valve mustoperate to admit scavenging air into the pump from atmosphere throughthe air filter 56. Simultaneously, with this scavenging air transferperiod, the air transfer valve must also operate to pass atmospheric airdirectly to one of the engine intake manifolds. During the period whenthe one air transfer valve is in position to pass compressed air fromthe pump to one engine intake manifold, the other air transfer valvemust be closed to cut off additional spaces or escapes open to theoutside and to prevent transfer of compressed air into the other engineintake manifold. It will be noted that the period in which intake ofscavenging air to the pump takes place coincides for a short time withthe period in which intake of atmospheric air takes place to another ofthe cylinders beginning its intake period. Both of these atmospheric airintakes may be served by the same air transfer valve, or in part by bothvalves.

To some extent the valve timings of a particular pump design may differfrom those illustrated. However, the valve timings must always be suchas to avoid upsetting interference between the different pressure wavesby which the pump operates. Special attention must also be given todesigning the engine discharge system so as to prevent the building upof a back pressure in one of the two engine exhaust manifoldsparticularly during periods when puff waves are being transferred fromthe other manifold into the pump space. The concentric discharge nozzles58 and 60 and the expanding Venturi throat 62 have been provided for thespecific purpose of promoting rapid and powerful scavenging of the pumpsystem while avoiding development of back pressure opposing the strokeexhausts.

The shafts I2 and 14 which, respectively, actuate the hot and cold gastransfer valves, are supported within the valve chambers by ballbearings 16. The bearings supporting the shaft 12 for the hot gastransfer valves may be protected by water jackets 18 against excessiveheat. Also, the hot valve shaft bearings may be protected against gasleakage by labyrinth gaskets (Fig. I). The bearings for supporting thecold gas transfer valve shaft 14 may be protected against gas leakage bythe usual type of bushings 19 with oil sealing, which has been found toprovide sufficient tightness for cold gas pressures never fluctuatingbetween positive and negative pressure maxima of more than a few poundsper square inch.

Each of the hot gas and cold air transfer valves is shown in Figs. I,III, IV, V and VI, in the position which it assumes just prior totermination of the displacement compression operation period (1-2) ofFig. II. During this period the hot puff exhaust gases from cylinder 1and manifold 26 are being transferred past valve 30 into pump 20.Simultaneously the valve 36 is in a position to transfer stroke exhaustgases from cylinder 4 and manifold 32 directly to atmosphere throughdischarge nozzle 50 and funnel 64. At this same time compressed air isbeing-transferred from the pump directly through valve 58, carbureter46, and air intake manifold 44, into cylinder 6. Also during thisperiod, air transfer valve 42 is in position for passing atmospheric airthrough carbureter 40 and manifold 38 into cylinder 2.

The air compression chamber of pump 20 as viewed in Fig. I, always liesto the right of piston 22, and is of annular cross section surroundingthe stem of the piston. The volumetric displacement of the pump 20,exclusive of the cubic displacement of the piston, which is relativelysmall, is never appreciably more than sufficient to handle the volume ofhot gas which is discharged from a single engine cylinder during thefirst puff discharge period, and to compress only the air with which acylinder is supercharged at the end of its air intake period.

The atmospheric air intake ports under the control of air transfervalves 42 and 48 have been illustrated as by-passed, respectively, witha pair of air by-pass conduits 84 and B6. Valves 88 and 9f) arerespectively mounted in conduits 84 and 86; and another valve 92 ismounted in the conduit 56 connecting the cold gas transfer valve housingwith the pump. Valves 88, 9B and 92 afford the means whereby engine Mcan be switched from normal operation to supercharging operation, orback to normal operation, at will. During supercharging valves 88 and 90are closed and valve 92 is opened, as shown in Fig. I. During normaloperation of the engine without supercharging, valve 92 is closed andvalves 88 and 90 are opened for passing atmospheric air di-v rectly andcontinuously from the air cleaner to the corresponding carbureters andengine intake manifolds.

The design of the pump-engine assembly illustrated in Fig. I is suchthat the displacement face of the pump piston is always exposed to theimpacts of the puff discharge waves from the engine cylinders. The wholesystem responds more rapidly to switching from atmospheric air intake tosupercharging when the hot gas side of the pump is continuouslysubjected to pulsating pressure. If, however, the operator desires toshield the pump during normal operation (without supercharging) againstthe hot puff exhaust waves, a by-pass 94 may be provided leading fromeach of the engine exhaust manifolds directly into the mufiier line(indicated in dotted lines in Fig. I), and special valves 96 may beprovided which on opening by-pass the exhaust pufi waves directly intothe engine mufiler.

The diaphragm of the pump illustrated in Fig. VII has been shown asslidably journaled on a post 45 which is mounted on the main axis of thepump with its ends supported by the end walls of the pump. A preferreddesign of the single diaphragm piston pump, however, has been shown inFig. I, in which the piston 22 is attached rigidly at its center to oneend of a stem 23. The other end of stem 23 carries a pin on whichadjacent ends of two links 68 are pivotally hinged. The opposite ends oflinks 68 in turn carry pins on which are respectively hinged twooscillating rods 69. Rods 69 are in turn pivotally mounted on bracketsattached to the casing of the pump. The oscillating ends of rods 69, towhich links 68 are respectively connected, are connected together by aretractile spring Hi. An oil-sealed stuffing box 2| is mounted in anaperture in the end plate of the pump within which stem 23 isreciprocably journaled.

During the compression period of each pump cycle all of the air which istrapped between the pump diaphragm and the air intake port of theintaking engine cylinder is subjected to compression by the fulldischarge gas wave. During the second half of the pump cycle, when thefull discharge wave is subsiding by reexpansion from the pump, theforces acting on the diaphragm to move it in the opposite directioninclude the suction developed in the Venturi exhaust orifice 62 by thestroke exhaust from one engine cylinder, and also the expansion force ofthe compressed air still trapped between the engine cylinder intakevalve which has just closed and the pump diaphragm. The pressure of theair thus trapped is rapidly reduced to atmospheric pressure by thecomplete expansion of the engine exhaust gases on the other side of thediaphragm, so that there is a tendency for the diaphragm movement toterminate somewhere in mid-stroke, without the aid of a device such asthe spring 70. The air pressure on the air side of the diaphragm israpidly reduced for another additional reason, and that is, that duringthe air rebound period of the diaphragm of the pumps shown in Figs. Iand VII, a second cylinder of the engine is beginning its air intakeperiod.

The spring of the piston return mechanism illustrated in Fig. I has beendesigned as an energy absorbing element which converts to mechanicalenergy a small part of the energy imparted to the piston during thedisplacement period of the pump cycle, by building up tension on thespring. The spring need only be strong enough to absorb a very smallproportion of the energy imparted to the piston. The construction of thespring mechanism is such that the farther the piston moves toward theright (as viewed in Fig. I) the smaller the amount of opposition tomovement of the piston. In other words, the spring has no effectwhatsoever on movement of the piston at the time that the piston hasreached the position shown in Fig. I, that is, when the back pressure ofthe compressed air is greatest. However, the spring exerts its fullforce against the piston when the piston is near the end point of itstravel toward the extreme left hand position within the pump. The onlyforces bearing on the piston in the position shown in Fig. I are thebalancing gas pressures on opposite sides thereof. On release of thetrapped exhaust gases lying to the left of the piston at the end of thedisplacement compression period, the piston will start to move backwardtowards the left hand side of its path of travel, and the tension on thespring then comes into action to draw the oscillating ends of the links69 toward each other, forcing the piston toward its extreme left handposition and thereby producing air scavenging of the pump. During fullspeed operation of the piston, in a pump-engine assembly such asillustrated in Fig. I, the piston of the pump will not travel the fulllength of its stroke, the length of the path of travel which it doestraverse depending on the exact dynamics of the particular pump designand on the speed of the engine and pump.

The floating diaphragms of the pumps shown in Figs. I, VII, X, XI, XVI,XVII and XVIII are circular metal discs, While the diaphragms of thepumps illustrated in Figs. VIII, IX have a rectangular shape. In allcases the pump diaphragms are dimensioned to reciprocate within the pumphousings with a definite small clearance between the walls of thehousing and the edges of the diaphragms. Very little leakage of gasoccurs past the diaphragm through such small clearance space during theoperation of the pump, since the gas pressure dilferential betweenopposite faces of the diaphragm is always very small. In fact suchpressure differential is only sufficient to overcome any inertiaresistance of the floating diaphragm, which is kept as small aspossible. The displacement pumps are preferably designed with a largecross-sectional area in comparison with the diaphragm stroke, for thepurpose of reducing the diaphragm speed and the inertia forces operatingon the diaphragm to a minimum. This construction also has the effect ofmagnifying any motive force impressed on the diaphragm and givinginstantaneous response of the diaphragm to any gas pressure differentialimpressed thereon.

In the pump modification which is illustrated in Figs. VIII and IX, thesheet metal diaphragm H has its ends rigidly attached to the shell ofthe pump and has sufficient elasticity to provide for' a self-flexingoperation between the full line position and the dotted line position.The method of suspending the ends of the diaphragm with respect to thepump housing of Figs. VIII and IX must be such as to allow for free playof the elastic self-retroactive properties of the diaphragm at anyinstant of the pump operating cycle.

In the pump-engine assembly which is illustrated in Fig. VIII, 2. pumpof the flexible diaphragm type is Shown as connected between exhaustmanifold 25 for cylinders 1, 2 and 3 of the engine and intake manifold Mfor cylinders 1, 5 and 6. Interposed between carburetor 46 supplying theintake manifold and air transfer conduit 51 for the pump, is a valvechamber in which valves 49 and 63 are rotatably mounted on shaft 13.Valve 43 controls transfer of compressed air from the pump to themanifold and also controls flow of atmospheric air to the manifold byway of port 83. Valve 63 controls supply of scavenging air to the pumpfrom atmosphere through conduit 51. The pump diaphragm and valves 49 and63 are shown in the positions which they assume near the end of the pumpscavenging period while air is being delivered from atmosphere both tothe pump and the intake manifold. This assembly is designed foroperation without hot valve control of transfer of exhaust gases betweenthe pump and the manifold 26 and between the exhaust manifold andatmosphere by way of a restricted discharge nozzle 59, Venturi throat 62and mufiier 64, as hereinafter more particularly described withreference to Fig. XVII. While not illustrated, it will be understoodthat a complete assembly would normally include a second diaphragm pumpinterposed between exhaust manifold 32 for cylinders 4, and 6 and intakemanifold 38 for cylinders 1, 2 and 3, the general method of assemblybeing illustrated in Fig. XVII. In the tandem pumps which areillustrated in Figs. X to XVIII, the energizing gas intake ports may belocated either at adjacent ends of the two pumps or at opposite sidecovers of the two pumps.

In the apparatus assemblies which are illustrated in Figs. X, XI, XVI,XVII and XVIII, two displacement pumps are mounted in tandem with theirfloating pistons connected by a common stem and interlocked forreciprocation in unison. The two pumps are designed for operation onalternate cycles, so that the displacement period in the operating cycleof one pump coincides with the air scavenging period in the cycle of theother pump, the interlocked pistons functioning to make both thedisplacement and the scavenging entirely positive. Each pump isoperatively connected to only one of the two exhaust manifolds of thesix cylinder engine, so

that each pump performs only half the number of cycles that are requiredof the single pump in the assemblies illustrated by Figs. I and VII. Inother words, each pump of the double pump assemblies illustratedperforms a number of cycles corresponding to 1 engine crank shaft speed(as compared to a pump cycle speed three times crank shaft speed for thesingle pump assembly of Figs. I and VII), and the gas and air transfervalves, when equipped with singlephased ports, also revolve at 1 enginecrank shaft speed.

In the assemblies illustrated by Figs. X, XI, XVI, XVII and XVIII,exhaust manifold 26 (for cylinders 1, 2 and 3) is in open and constantcommunication with one of the pumps by means of a hot gas transferconduit 5|; while the other exhaust manifold 32 (for cylinders 4, 5 and6) is in open and constant communication with the other pump 20, bymeans of a separate hot gas transfer conduit 53. The floating pistons 22for the two pumps are preferably light alloy metal discs rigidly mountedon a common stem 61 which is, in turn, reciprocally supported bylubricated bushings and stuffing boxes 21 which are centrally mounted inthe end plates of each pump housing and are always cooled by air beingpumped. The working chambers of the .two pumps shown in Figs. X, XI,XVII and XVIII are disposed in tandem within a single housing,

on opposite sides of an'inclined partition 130. In Figs. XVI, the twopumps are arranged in tandem, each pump within its individual housing.

Manifold 25 is ported out (Figs. X, XI, XVI and XVIII) at 21 into thehousing of a cylindrical gas discharge valve 3|; and manifold 32 issimilarly ported out at 33 into the housing of a cylindrical gasdischarge valve 31. Transfer conduits 5l and 53 are ported out into therespective pumps with which they communicate at adjacent ends of the twopumps (Fig. XVI); or, in the case of Figs. X, XI, XVII and XVIII, atsymmetrical points located at opposite sides of partition I50.

One engine intake manifold 38 (for cylinders l, 2 and 3) is shown asconnected through a carbureter 43 to the housing of a single-portedtubular air transfer control valve 43; while the other intake manifold44 (for cylinders 4, 5 and. 6) is connected through a carbureter 46 tothe housing of an air transfer control valve 49. The housings of valves43 and 49 are respectively connected to the respective displacementpumps 20 by air transfer conduits 55 and 51. It will be noted that hotgas transfer conduits 5| and 53 are ported out into the respective pumps23, with which they communicate, at adjacent sides of the pump pistons22; and that the air or cold gas transfer conduits 55 and 51 are portedout into the respective pumps at the remote sides of the correspondingpump pistons. V

Concentric gas ejector nozzles 63 and 58 are connected respectively tothe housing of hot gas discharge control valves 3| and 31 and afford themeans by which gas may be discharged from the exhaust manifolds, and thepumps connected therewith, to atmosphere by way of the Venturi throat 62and muffler 64.

Each of the air transfer conduits 55 and 51 is ported out into thecommon housing for a pair of air transfer control valves 63 and 65,which are single-ported tubular valves. Valves 63 and 65 are mounted torespectively control transfer of atmospheric air for scavenging thepumps from an air intake filter 66 to one of the conduits 51 and 55,while blocking transfer of atmospheric air to the other transferconduit.

In the apparatus of Figs. X, XI, XII, XIV, XV and XVIII, conduits 55 and51 are forked. The main forks of the respective conduits lead directlyfrom the pumps to the corresponding atmospheric air control valves 63,65. The other forks 82 (of conduit 55) and 99 (of conduit 51) branch outof the main fork at points near the pump and lead up to the ports oftransfer valve 43, 49.

Apair of air by-pass chambers 8| and 83 has been illustrated in Figs. Xand XVI. These bypass chambers are ported out at each side of air filter35. Communication between chamber BI and intake manifold 38 is under thecontrol of valve 43, while communication between chamber 83 and theintake manifold 44 is under the control of valve 43. For supplyingatmospheric air to the intake manifolds of the engine throughout theentire air intake period, in case pumps 23 are not operatively connectedto deliver supercharge air during part of the intake period, bypasspipes 35 and 81 are provided, respectively connecting chambers 8| and 83to the intake manifolds 38 and 4d, by-passing valves 43 and 49. Abutterfly valve 89 is mounted in pipe 85, and a similar valve Si ismounted in pipe 81. A valve 93 is mounted in fork 82 of the air transferconduit 55 (Fig. XV), and a similar valve 95 is mounted in fork $9 ofair transfer conduit 51 (Figs. X, XII). Valves $3 and 95 when closedblock transfer of compressed air from the pump to the engine intakemanifolds. Valves 89, 9i, 93 and 95 afford the means whereby the enginecan be switched from normal operation to supercharging operation, orback to normal operation, at will. During supercharging, valves 89 and9! are closed, and valves 93 and '95 are open. During normal operationof the engine without supercharging, valves 93 and 55 are closed andvalves 89 and El are open.

I-Iot gas transfer valves 36 and 3! (Figs. X, XI and XVI) are mounted ona single drive shaft ii, Likewise, air or cold gas control valves 43, E3and B are all mounted on a single drive shaft '53. Shafts TI and 13 areoperatively connected for actuating all of the hot gas and air transfercontrol valves directly from the crank shaft of the internal combustionengine. The shaft H for the hot gas valves is supported within the valvechambers by ball bearing 75, and these ball b rings are protected bywater jackets l5 against excessive heat (Fig. X). Also the hot valveshaft bearings are protected against 'g'as leakage by labyrinth gaskets'88. The bearings for supporting the air or cold gas transfer valveshaft 73 are protected against gas leakage by the usual type of bushings1'3 with oil sealing.

In the schematic pumps and six cy 'nder engine shown by Fig. XVIL'hottransfer control valves have been omitted, and in place thereof therehave been substituted a pair of gas "6i of predetermined restrictedcross-section, which may be located in the same relative position as arethe gas discharge nozzles 58 and 69 of the assemblies portrayed in Figs.X, XI, XVI and XVIII.

illustrated in Fig. XVII, has been particularly designed for operationat substantially constant speed. The cross sectional area of each of thedischarge nozzles 55% and ii! is so chosen as to just handle the volumeof gas discharged from an engine cy nder during the exhaust periodwithout developing substantial back pressure during the stroke period ofthe exhaust. Conse quently, because of the restricted area of thesenozzles "59 and i, th 4y have'a considerable blocking effect agains thestrong pufi exhaust wave which exits fr m an engine cylinder during thefirst or puff period of the exhaust cycle. As a result 'of the partialblocking effected by nozzles 59 and 5!, a supercharging p essure ofmoderate intensity is impressed on the piston'of whichever one of thepumps is connected to the manifold receiving that particular puffdischarge wave. The reduction in compression efficiency or intensitywhich is obtai' ed by the design of Figs. VIII and XVII, in comparisonwith the assemblies of Figs. X, XI, XVI and XVIII, may in some cases bejustified by the greater simplification of apparatus which results fromthe elimination of the hot gas transfer control valves.

Each of the hot gas and cold air transfer valves is shown in Figs. X toXV, inclusive, in the position which it assumes just prior totermination 72 of the displacement compression operation period ab ofFig. II. During this period the hot puff exhaust gases from one of theengine cylinders, for example cylinder 1, are being transferred directlyfrom manifold 25 into the pump Ell which is connected with thatmanifold. Simultaneously, valve 3? is in position to transfer strokeexhaust gases from cylinder 4 and maniassembly of two displacement"ejector nozzles 5-9 and The modified assembly, which is,

fold 32 directly to atmosphere through discharge nozzle 58 and funnel52. At this same time, compressed air is being transferred from thechamber in the same pump at the opposite side of the piston directlypast valve 49, carbureter 4.6 and air intake manifold 44, into cylinder6. Also during this period, air transfer valves 63 and 65 are inposition for passing atmospheric air from air cleaner 66 throughtransfer conduit 55 into the air chamber side of the second pumpconnected with manifold 22 during the scavenging period of the cycle ofthis second pump.

Positive scavenging of the displacement pump with a fresh charge of airduring the last part of each pump cycle is assured by providing the pumppiston with a spring fly-wheel construction such as shown in Fig. I, orby providing the pump with a flexing diaphragm ll as shown in Figs, VIIIand IX, or by connecting the piston with the piston of another pump(Figs. X, XI, XVI, and XVII) in such a manner that the-first piston ismoved on a suction stroke by the second piston operating on itsdisplacement stroke. The discharge nozzles 53 and -98 are disposed inconcentric relation at the entrance of the Venturi funnel -52 to assistscavenging of the pumps by applying the suction aspiration effect of ajet of engine exhaust gases discharged directly from one engine exhaustmanifold to atmosphere through one of said nozzles during the strokeexhaust period of "an engine cylinder connected to s id manifold forpromoting development of suction in the pump connected to the otherexhaust nozzle during the scavenging period of the pump cycle. Anyinterference to pump scavenging which may be offered by air cleaner 66may be compensated by mounting a fan 32 (Fig. XVI) at the entrance ofthe air cleaner to supply air thereto under slight pressure.

The invention having been thus described, what is claimed as new is:

1. In an energy conversion operation the steps comprising, explodingcombustible charges of air and fuel successively in regular sequence atrapidly repeated intervals in a plurality of combustion zones,converting part of the energy liberated by each explosion to mechanicalenergy within the combustion zone, discharging gaseous combustionproducts after each such explosion and partial energy conversionoperation while still under pressure into a confined moving stream ofsuch products under 'a lower average superatmospheric pressure than theoriginal discharge pressure, thereby building up pressure waves in saidstream following each'other with a frequency corresponding to thefrequency of the explosions, impressing the pressure wavesthus'developed in said stream against one side of a movable partitic-nthereby effecting displacement movement there-of while simultaneouslyflowing air under substantially atmospheric pressure in a confinedstream in contact with the other side "of said partition, and therebydeveloping pressure waves of the same frequency and substantially thesame magnitude in the air stream.

2. In power developing apparatus, a high-speed internal combustionengine having a plurality of cylinders arranged in groups, each cylindergroup comprising cylinders which have non-overlapping suction periodsand non-overlapping ex- ..haust periods, a separate intake manifold anda of said compressor and an intake manifold of one cylinder group, a hotexhaust gas transfer connection between the other end of said compressorand an exhaust manifold of a second cylinder group, valves mounted inposition for controlling transfer of gas and air through said transferconnections, and valve timing and actuating mechanism for operating saidvalves to effect simultaneous transfer of compressed air from thecompressor to one engine cylinder near the end of its suction period,while transferring engine exhaust gases to the compressor from anothercylinder during the first part of its exhaust period.

3. In power developing apparatus, a multicylinder four cycle internalcombustion engine having its cylinders arranged in groups, each cylindergroup consisting of cylinders which have non-overlapping suction periodsand non-overlapping exhaust periods, a separate intake manifold and aseparate exhaust manifold for each cylinder group, a plurality ofdisplacement air compressors, each compressor comprising a cylinderhaving a light weight metal piston mounted for reciprocal movementtherein, the pistons in each pair of compressors being affixed to acommon reciprocable stem for movement in unison, air transferconnections between an end of each compressor and an intake manifold ofone cylinder group, a hot exhaust gas transfer connection between theopposite end of each compressor and an exhaust manifold of anothercylinder group, and control valves for regulating the transfer of gasand air into and out of each compressor through said transferconnections.

4. In an energy conversion operation wherein a highly compressed chargemixture of air and fuel is exploded and partially expanded in oneconversion zone while simultaneously introducing a fresh air charge intoa second conversion zone, the steps comprising, trapping a body of airunder low pressure at one side of a movable partition during the firstpart of the air charging period of the second zone, during the last partof the air charging period of the second zone discharging hot gaseousproducts of combustion from the first conversion zone still undersuperatmospheric pressure in a rapidly advancing wave against the otherside of said partition, thereby displacing said partition andcompressing the trapped air body by pressure balancing displacement,transferring the compressed air body as supercharge air directly intothe second conversion zone while moving said partition ahead of theadvancing hot gas wave, and at the end of the supercharging perioddischarging exhaust gases from the gas side of the partition andtrapping a fresh supply of air on the air side thereof while returningthe partition to its original position preparatory to a new cycle.

5. In an energy conversion operation wherein cylinders of amulticylinder internal combustion engine operate on explosion powerstrokes following each other in regular sequence the steps comprising,discharging gaseous products of combustion while still under pressure,from said cylinders in a confined moving stream of such products under alower average superatmospheric pressure than the original dischargepressure thereby building up pressure waves in said stream followingeach other with a frequency corresponding to the frequency of theexplosions, impressing a pressure wave thus developed in said streamagainst one side of a movable partition while simultaneously trappingair at substantially atmospheric pressure in contact with the other sideof the partition and compressing the air by movement of the partitionahead of the advancing gas pressure wave, releasing the compressed airwhile trapping the gas against escape, and after each period ofcompressed air release expanding gas from said stream to atmosphere andreturning the partition to substantially its original positionpreliminary to a new cycle during the period of the following pressurewave.

6. In an energy conversion operation wherein cylinders of amulticylinder internal combustion engine operate on power strokesfollowing each other in regular sequence with one cylinder commencingits gas exhaust period while a second cylinder is finishing its airintake period, the steps comprising, trapping a body of air under lowpressure at one side of a movable partition during the first part of theair intake period of the second cylinder, during the last part of theair intake period or the second cylinder discharging a rapidly advancingpressure wave of hot gaseous products of combustion from the firstcylinder at the commencement or its waste gas discharge period againstthe other side of said partition, thereby displacing said partition andcompressing the trapped air body by pressure balancing displacen at,transferring the compressed air body as supercnarge air directly intothe cylinder taking in air wnne moving said partition ahead of theadvancing hot gas wave, and at the end of the super-charging perioddischarging exhaust gases iroin the gas side of the partition andtrapping a fresh supply or air on the air side thereof while returningthe partition to its original position in the period remaining beforeanother pair of cylinders begin their supercharging and gas exhaustperiods, respectively.

'1. in an energy conversion operation wherein cylinders of amulticylinder internal combustion engine operate on power strokesfollowing each other in regular sequence with one cylinder commencingits gas exhaust period while a second cylinder is finishing its airintake period, the steps comprising, setting up flow of air fromatmosphere to the second cylinder during the first part of its airintake period and simultaneously bypassing air from said stream intocontact with one side of a movable partition and trapping said bypassedair, during the last part of the air intake period of the secondcylinder discharging hot gaseous products of combustion from the firstcylinder at the commencement of its waste gas discharge period as arapidly advancing pressure wave against the other side of said partitionthereby displacing said partition and compressing the trapped air bodyby pressure balancing displacement, transferring the compressed air bodyas supercharge air directly into the second cylinder while movingsaid'partition ahead of the advancing hot gas wave, and at the end ofthe supercharging period discharging exhaust gases from the gas side ofthe partition while returning the partition to its original positionpreliminary to a new cycle.

8. The method of supercharging the cylinders of a multicylinder internalcombustion engine which comprises, maintaining a body of air undersubstantially constant low pressure in contact with one side of areciprocable diaphragm partition while transferring air therefrom into acylinder during the first portion of its air intake period, during thelast part of the air intake period boosting the pressure of said airbody and ramming the thus compressed air body as a supercharge into saidcylinder, and carrying out said pressure boosting and ramming operationby pressure balancing displacement of the air by a rapidly advancingwave of hot gaseous products of combustion discharged under highpressure against the other side of the diaphragm from a second cylinderat the commencement of its waste gas discharge period.

9. In energy conversion apparatus, a multicylinder four cycle internalcombustion engine having a plurality of cylinders with pistonsreciprocably mounted therein and timed for operation in sequence with acrank angle spacing of at least 180, valved exhaust ports for eachcylinder, an exhaust manifold connecting the exhaust ports of all ofsaid cylinders, a displacement air compressor comprising a chamberhaving a diaphragm partition mounted transversely therein and arrangedfor reciprocation in response to slight gas pressure differentialsbetween opposite sides thereof, an air supply conduit arranged to supplyreplenish air at low pressure to one side of said partition, acompressed air removal conduit connected to the same side of thediaphragm, an exhaust gas transfer conduit communicably connecting theengine exhaust manifold to the other side of the partition, a gasdischarge conduit connected to the exhaust gas side of the partition,and valve mechanism arranged for actuation and timing by the engine tosynchronize the periods of exhaust gas transfer to the compressor and ofcompressed air removal therefrom and to interrupt each such period ofgas transfer and air removal while simultaneously connecting thecompressor with the gas discharge and air supply conduits for compressorscavenging preliminary to a new cycle.

10. In energy conversion apparatus, a multicylinder internal combustionengine having a plurality of cylinders with pistons reciprocably mountedtherein and timed for operation in sequence with nonoverlapping gasexhaust periods, an exhaust port and an intake port for each cylinder, adisplacement air compressor comprising a chamber and a diaphragmpartition mounted transversely in the chamber and arranged forreciprocation therein in response to slight gas pressure diiferentialsbetween opposite sides thereof, a gas transfer conduit communicablyconnecting the compressor at one side of the diaphragm with the exhaustports of said engine cylinders, a restricted outlet from said conduit toatmosphere, compressed air removal and replenish air supply conduitsconnected to the compressor at the other side of said diaphragm, andvalve mechanism arranged for actuation and timing by the engine tosynchronize the discharge of compressed air from the compressor with thefirst part of a cylinder gas exhaust period.

11. In power developing apparatus, a multicylinder internal combustionengine having a plurality of cylinders with pistons reciprocably mountedtherein and timed for operation in sequence with nonoverlapping gasexhaust periods, an exhaust port and an intake port for each cylinder, adisplacement air compressor comprising a chamber, a diaphragm partitionmounted transversely in the chamber and arranged for reciprocation inresponse to slight gas pressure difierentials between opposite sidesthereof, a gas transfer conduit communicably connecting the compressorat one side of the diaphragm with the exhaust ports of said enginecylinders, a compressed air removal conduit connected with thecompressor at the other side of said diaphragm, and mechanismoperatively connected with the diaphragm and arranged for absorbingenergy imparted to the diaphragm during movement thereof in onedirection and for transferring energy to the diaphragm for moving it inthe opposite direction.

12. In energy conversion apparatus, an internal combustion engine havingoperatively paired cylinders with pistons mounted therein, an exhaustport and an air intake port for each cylinder, said paired cylindersbeing timed for operation of one cylinder on the last part of its airintake period while the second paired cylinder is commencing its gasexhaust period, a displacement air compressor comprising a wall-enclosedchamber, a diaphragm partition mounted transversely in the chamberintermediate the ends thereof and arranged for reciprocation therein inresponse to slight pressure difierentials between opposite sidesthereof, a pressure gas transfer conduit connecting the exhaust port ofthe second cylinder with one end of the compressor, a gas dischargeconduit connected to the same end of the compressor, an air transferconduit connecting the intake port of the first cylinder with the otherend of the compressor, an air supply conduit connected to that end ofthe compressor, and valve mechanism arranged for actuation and timing bythe engine to simultaneously connect the cylinders through said transferconduits with the displacement compressor at a supercharging period ofthe cycle and to subsequently block such connections and effectsimultaneous connection of the compressor with the gas discharge and airintake conduits for compressor scavenging preliminary to a new cycle.

JOI-IANN J. WYDLER.

